staging: vt6656: Fix sparse warnings

This patch fixes the following sparse warnings:
drivers/staging/vt6656/aes_ccmp.c:272:32: warning: restricted __le16 degrades to integer
drivers/staging/vt6656/aes_ccmp.c:274:32: warning: restricted __le16 degrades to integer
drivers/staging/vt6656/aes_ccmp.c:282:32: warning: restricted __le16 degrades to integer

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>